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Show CHAPTER 7 FUTURE WORK AND CONCLUSIONS 7.1 Future Work There is much work that remains to be done in the area of virtual databases. This work relates both to the advancement of virtual database technology in general and to specific tasks that must be accomplished to develop a production version of the virtual database for HELP. The prototype of a virtual database that was developed and studied in this work was a read-only database. A read/write database was not required because the standard database to which virtual database technology was applied was an archival database. The general virtual-database solution must provide a database that can be modified. Modifications of the database can occur in three ways: elements of data can be added to the database; elements of data can be deleted from the database; and elements of data can be modified in the database. If any of these modifications occur in the virtual file of a virtual database, they must also occur in the physical file of the virtual database. If modifications are not propogated to the physical file of the virtual database, then it would no longer be true that the virtual file is logically equivalent to the physical file, and the fundamental property of a virtual database system would be violated. |
